HIGH-POWER TUNABLE FEMTOSECOND VISIBLE AND INFRARED LIGHT FROM A SYNCHRONIZED TI-SAPPHIRE ND-YAG LASER SYSTEM BY DIFFERENCE-FREQUENCY MIXING

High power, 20 Hz repetition rate difference frequency mixing of exter nally synchronized femtosecond Ti:sapphire laser radiation with harmon ics of a phase locked picosecond Nd:YAG laser, in a BBO crystal, is sh own to produce femtosecond pulses in the visible (666 nm) and infrared (1.77 mu m) regions. Using 50 mu J of 760 nm amplified Ti:sapphire li ght, outputs of tens of microjoules at 666 nm, or several microjoules at 1.77 mu m, were achieved. This technique can be used to extend the tuning range (720-1000 nm) of the Ti:sapphire laser into the visible ( 550-700 nm) and the infrared (1.1-2.0 mu m) regions of the spectrum.